在java.util中获取错误ArrayList不带参数[重复]

我已经创建了一个类“Student”，现在我尝试将我的 Student 对象存储在 ArrayList 中，但在编译 ArrayList 不接受参数时出现错误。我已经检查了我的代码很多次，但找不到问题所在。

我的学生班级是这样的

public class Student
{
//declaring variables 
private int rollNumber ;
private String name ;


//a counter for counting how many students or objects are declaired yet
public static int studentCount = 0;
public static int getStudentCount()
{
    return studentCount;
}


//getters for both variables
public int getRollNumber()
{
    return rollNumber;
}
public String getName()
{
    return name;
}


//setters for both variables 
public void setRollNumber(int x)
{
    if (x > 0)
    {
        this.rollNumber = x;
    }
    else
    {
        System.out.println("Wrong Roll Number Value");
    }
}
public void setName(String someName)
{
    this.name = someName;
}


//default constructor
public Student()
{
    setName("Please Enter A Name");
    this.rollNumber = 0;
    studentCount +=1;
}


//parameterized constructor
public Student(String name, int x)
{
    setName(name);
    setRollNumber(x);
    studentCount += 1;
}


//copy constructor
public Student(Student s)
{
    setName(s.name);
    setRollNumber(s.rollNumber);
    studentCount +=1;
}

//defining an print method 
public void print()
{
    System.out.println("Student Name = " + name + "______Roll Number = " + rollNumber);
}
}

我正在实施它的课程如下

import java.util.*;

public class ArrayList
{
    public static void main (String[] anyString)
{
    //Creating Some student objects
    Student s1 = new Student("Ammar" , 1);
    Student s2 = new Student("Ahmad" , 2);
    Student s3 = new Student("Arslan", 3);


    //Creating an arraylist
    ArrayList<Student> someList= new ArrayList<Student>();


    //checking if our Array List is empty or not 
    boolean empty = someList.isEmpty();
    if (empty == true)
        System.out.println("ArrayList is Empty \n\n");


    //adding our student class objects to our arraylist
    someList.add(s1);
    someList.add(s2);
    someList.add(s3);


    //checking if arraylist is empty or not 
    empty = someList.isEmpty();
    if (empty == true)
        System.out.println("ArrayList is Empty");
    else
    //counting total members in a list 
    System.out.println("Our ArrayList someList have a total of " +someList.size() + " Members \n\n");


    //geting back objects from arraylist or extractin them from list 
    //we will display our objects to console one by one 
    for (int i = 0; i < someList.size() ; i++)
    {
        Student one = someList.get(i);
        one.print();
    }
}
}

已清理并更名。

import java.util.ArrayList;

public class Student
{
  String name;

  int id;

  public Student(String name, int id)
  {
    this.name = name;
    this.id = id;
  }

  public static void main(String[] anyString)
  {
    // Creating Some student objects
    Student s1 = new Student("Ammar", 1);
    Student s2 = new Student("Ahmad", 2);
    Student s3 = new Student("Arslan", 3);

    // Creating an arraylist
    ArrayList<Student> someList = new ArrayList<Student>();

    // checking if our Array List is empty or not
    boolean empty = someList.isEmpty();
    if (empty == true)
      System.out.println("ArrayList is Empty \n\n");

    // adding our student class objects to our arraylist
    someList.add(s1);
    someList.add(s2);
    someList.add(s3);

    // checking if arraylist is empty or not
    if (someList.isEmpty())
      System.out.println("ArrayList is Empty");
    else
      // counting total members in a list
      System.out.printf("Our ArrayList someList has a total of %d Members \n\n",
          someList.size());

    // geting back objects from arraylist or extracting them from list
    // we will display our objects to console one by one
    for (Student student : someList)
    {
      System.out.println(student);
    }
  }

  @Override
  public String toString()
  {
    return "Student [name=" + name + ", id=" + id + "]";
  }
}